* A new line discipline has been added in order to leave untouched the serial ports code (as suggested by Alan).

* n_tty.c exports only GPL symbols.

* ioctl numbers fixed in order to avoid any conflicts.

* Last patch (0010-PPS-low-level-IRQ-timestamps-recording.patch) implements low level IRQs timestamps recording which mproves PPS precision but can be dropped for kernel inclusion! As suggested by Alan: "After that is sorted/merged we can come back to working out the best way to improve the IRQ and HARDPPS hacks."